This invention relates to the most stable crystalline polymorph Form I of (−)-4-[4-[4-[4-[[(2R-cis)-5-(2,4-difluorophenyl)tetrahydro-5-(1H-1,2,4-triazol-1-ylmethyl)furan-3-yl]methoxy]phenyl]-1-piperazinyl]phenyl-2,4-dihydro-2-[(S)-1-ethyl-2(S)-hydroxylpropyl]-3H-1,2,4-triazol-3-one represented by the formula I (hereinafter “the compound of formula I”) pharmaceutical compositions containing such polymorph and methods of using such polymorph to treat fungal infections in mammals.
International Publication Numbers WO/95/17407(published 29 Jun. 1995 and WO 96/38443(published 5 Dec. 1996) disclose methods of making the compound of formula I and using it to treat antifungal infections in mammals. These International Patent Publications do not disclose or refer to, or even suggest the possible existence of a crystalline polymorph of the compound of formula I; the synthetic procedures disclosed therein produce the compound of formula I as an amorphous solid.
To prepare pharmaceutical compositions containing the compound of formula I for administration to mammals in accordance with exacting health registration requirements of the U.S. and international health registration authorities, e.g. the FDA's Good Manufacturing Practices(“GMP”)requirements, there is a need to produce the compound of formula I in as pure a form as possible, especially a form having constant physical properties.